Indirect excitation and luminescence activation mechanisms of rare-earth doped wide bandgap degenerated semiconductors and their impact on the host s optical and electrical properties
Abstract
The present proposal aims to systematically study thermal activation and host-mediatedrare-earth (RE) indirect excitation mechanisms in sputtered Indium Tin Oxide (ITO) andAluminum doped Zinc Oxide (AZO) thin films embedded with Terbium (Tb) and Thulium(Tm) impurities. These are direct wide bandgap degenerated semiconductors that havethe potential to combine low electrical resistivity and high visible optical transmittance,with light emission features, when doped with REs. There are only a few reports wherea transparent conductive oxide has been doped with REs. In these cases, very little orno light emission was observed.14 In addition, there is a lack of consensus on theexcitation and activation mechanisms of RE-doped, wide-bandgap materials. Here, wedevelop new dispersion models to describe the absorption edge and complex refractiveindex considering excitonic effects, coupled to Drude, Lorentz and direct fundamentalabsorption processes. Our models will be experimentally tested and will serve as aplatform to assess the RE indirect excitation mechanism via the formation of boundexcitons to RE clusters in these materials. We expect to make the latter excitationmechanism evident by inducing the thermal quenching of the RE-related luminescencein a temperature range in which excitons cannot exist, thus determining the excitonicbinding energy for RE clusters with different sizes.Our project is aligned with the Dielectric Materials and Films ONR program and webelieve it substantially contributes to the U.S. objective of mitigating potential supplydisruption and lack of innovation in the area of RE materials. We aim to conductfundamental research in order to develop novel RE-doped, wide bandgap semiconductormaterials with optoelectronic properties that are suitable for applications in the naval,military and defense fields, renewable energies, light emitting and sensing devices, gassensors and advanced optoelectronics. In addition, we will contribute to developing thefundamental knowledge of the physical properties and mechanisms of the RE-basedmaterials, as well as in training scientists, engineers and educators, to enhance RErelated research, innovation and education.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 05, 2021
- Source ID
- N629092112034
Entities
People
- Jorge Andrés Guerra Torres
Organizations
- Office of Naval Research
- Pontifical Catholic University of Peru
- United States Navy